b2 genetic disorders

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  • Created by: Avaaa
  • Created on: 20-03-17 20:57
what can a difference in alleles lead to
• Different combinations of alleles may lead to differences in the characteristic
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some disorders are
inherited
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polydactly is
Polydactyly – having extra fingers or toes – and is hterfore caused by a dominant allele of a gene and can therefore be passed on by only one parent who has the disorder
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how does cystic fibrosis vary
Cystic fibrosis (a disorder of cell membranes) must be inherited from both parents. The parents may be carriers of the disorder without actually having the disorder themselves.
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it is caused by a
y a recessive allele of a gene and can therefore be passed on by parents, neither of whom has the disorder.
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how do embryos help in avoiding these disorders
Embryos can be screened for the alleles that cause these and other genetic disorders.
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whats a phenotype
is a description of how a characteristic is expressed. This can be influenced by genetic or environmental factors. •
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genotype..
• Genotype is a description of the alleles an individual possesses for a characteristic.
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a homozygous genotype is
• A homozygous genotype has 2 identical alleles
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a heterzygous is
• A heterozygous genotype has two different alleles for a gene.
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describ how sex is determined
• There is a 50% possibility of being a girl or a boy. • As a foetus, we all start off with female characteristics. • Presence of Y chromosome causes male development. • Absence of Y chromosome continues female development.
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sooooo
so the sex of the baby is determned by the father.
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Card 2

Front

some disorders are

Back

inherited

Card 3

Front

polydactly is

Back

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Card 4

Front

how does cystic fibrosis vary

Back

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Card 5

Front

it is caused by a

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